Magnetoresistive detection system and method for detection of magnetic image of bank notes

ABSTRACT

A system and method for obtaining a fill image of a bank note being processed. At least one magnetoresistive detector is employed to obtain line-scan sensings of a bank note as the note passes. A central processing unit obtains the sensing as magnetic pattern data which is subsequently stored in a database for processing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application from U.S. patentapplication Ser. No. 13/627,797 filed on Sep. 26, 2012, which is acontinuation of U.S. patent application Ser. No. 12/556,360, filed Sep.9, 2009, issued as U.S. Pat. No. 8,297,507, which claims the benefit ofprovisional Application No. 61/096,219, filed Sep. 11, 2008.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to automated currency processing and, morespecifically, to the automated imaging, through use of magnetoresistivedetectors, of bank notes undergoing high-speed processing.

2. Description of Related Art Including Information Disclosed Under 37CFR 1.97 and 1.98

In an effort to combat the counterfeiting of bank notes and othermachine-processable security documents, substrate manufactures continueto develop and incorporate new security features into their product.These security features include the utilization of embedded magneticstrips as well as magnetic inks with which to print the currency on thesubstrate.

Current bank note processing machines feature numerous detectors andsensors to determine various attributes of a bank note being processed.Such machines often incorporate a magnetoresistive detector that detectsthe embedded magnetic strip and/or magnetic ink on the face of the bill.However, current magnetoresistive detectors only detect the absence orpresence of such features which yields only limited information. What isneeded is a magnetoresistive detector that is capable of imaging theentire note such that the note's image may be retained as a record ormay be further examined by use of specialized imaging algorithms.

BRIEF SUMMARY OF THE INVENTION

A system for automatically detecting the magnetic features of a banknote, the system comprising: a transport device capable of transportinga bank note along a defined path; a data processing device capable ofexecuting stored program instructions; a data storage device operablycoupled with the data processing device; and a first detector deviceoperably coupled with the data processing device, the first detectordevice comprising a plurality of magnetoresistive sensors positionedproximate the transport device and oriented so as to enable detection ofthe magnetic features of the adjacent surface of the passing bank note.

A method for detecting the magnetic features of a bank note, the methodsteps comprising: transporting the bank note along a defined sport pathproximate to a first array of magnetoresistive detectors; repeatedlyreading the outputs from the first array of magnetoresistive detectorsas the note is adjacent thereto to obtain first surface magnetic patterndata of the surface of the passing note adjacent to the detector array;analyzing the first surface magnetic pattern data with a data processingdevice; and making a determination regarding final processing of thebank note based upon the first surface magnetic pattern data

These and other improvements will become apparent when the followingdetailed disclosure is read in light of the supplied drawings. Thissummary is not intended to limit the scope of the invention to anyparticular described embodiment or feature. It is merely intended tobriefly describe some of the key features to allow a reader to quicklyascertain the subject matter of this disclosure. The scope of theinvention is defined solely by the claims when read in light of thedetailed disclosure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The present invention will be more fully understood by reference to thefollowing detailed description of the preferred embodiments of thepresent invention when read in conjunction with the accompanyingdrawings, in which like reference numbers refer to like parts throughoutthe views, wherein:

FIG. 1 depicts a block diagram of a basic bank note processing machine,illustrating the location of magnetoresistive detectors within theprocessing stream;

FIG. 2A is an end-on depiction of a magnetoresistive detector devicewith a bank note passing beneath the sensor surface;

FIG. 2B is a top-down depiction of the magnetoresistive detector deviceand passing bank note; and

FIG. 3 is a flowchart representing the magnetoresistive detector deviceprocessing steps.

FIG. 4 is an end-on depiction of a two-detector magnetoresistivedetector device with a bank note passing between the two detectors;

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

DETAILED DESCRIPTION OF THE INVENTION

Typical currency processing machines comprise a bank note feeder device,a transport device or belt along which notes travel past severaldetectors, and a final disposition component, which comprises typicallya pocket for collection of processed notes, a strapper for strapping thenotes in bundles, and a means for depositing the notes into the pocketby pulling the notes from the note processing path or transport device.As the note is processed, detectors along the transport path scan thenote for various attributes.

The present invention utilizes a data processing device capable ofrunning stored program instructions and machine memory capable ofstoring program instructions. The data processing device may include oneor a combination of a general purpose computer, a CISC, RISC, or otherembedded controller, a DSP, or even programmable logic devices such asPALs, GALs, CPLDs, FPGAS, and the like. Data storage is provided byonboard semiconductor memory devices such as RAM or ROM ICs, and/ormagnetic storage such as hard drive storage devices, magnetic tapestorage devices, and the like.

The present invention utilizes a novel method for imaging an entire banknote printed with magnetic ink. Instead of merely providing anindication of the presence or absence of such magnetic ink or embeddedstrip, the present embodiment creates what is, in essence, a “snapshot”image of the entire note.

FIG. 1 depicts a simplified block diagram of a bank note processingmachine embodiment, highlighting the relative location of the noveldetectors (as claimed herein) with respect to the transport path. Thenote is propelled into the transport path by the feeder mechanism (102)where it enters the scanner module (106). The scanner transports thenote past a magnetoresistive detector device (104) in addition to otherdetectors (110). The detectors are configured to detect at least oneattribute of the note under examination.

FIGS. 2A and 2B depict a more detailed view of the magnetoresistivedetector (“MRD”) device. As depicted in FIG. 2A, the MRD of the presentinvention is configured with two 8-channel arrays of magnetoresistivesensors. By combining multiple arrays into a tightly packed device,multiple sensings of a note may occur which provides a higher resolutionoutput. Although this embodiment utilizes an 8-channel array, one ofordinary skill in the art will appreciate that a greater or lessernumber of sensors may be utilized without straying from the scope of theinvention herein.

FIG. 2A shows an end-on view of the bank note (202) as it passes the MRDdevice. The MRD consists of a sensor enclosure (204), which houses themagnetoresistive sensor array (208). The sensor array (208) spans thewidth of the bank note and is located sufficiently close to the banknote to enable detection of the note's magnetic features.

Although the present embodiment utilizes an array that spans the widthof the bank note, it is possible to use other arrays that may span onlya portion of the bank note. For example, it is possible to utilize twosix-channel array devices that each only cover three-fourths of thewidth of the bank note by staggering the two arrays such that one coversfrom the left side of the bank note and the other covers from the rightside of the bank note. The stagger will result in a magnetic patterndata mismatch and overlap that can be removed through subsequentprocessing by the data processor.

FIG. 2C depicts a top-down view of the bank note (202) passing throughthe detector (104). As the note (202) moves linearly past themagnetoresistive sensor array (208), the data processing circuitryobtains repeated readings from the array (208). The array (208) sensesmagnetic fluctuations caused by the various features of the note (202),such as the magnetic ink used in printing and the embedded magneticstripes and other such elements. As it is obtained, the magnetic patterndata is stored in the data storage device for subsequent processing.Image processing algorithms may then be applied to the sensed data toreconstruct the note. In the top-down view, only the first MRD device(204) is visible. In an embodiment having two MRD devices, the secondMRD device (not shown) would be mounted somewhere beneath the first MRDdevice (204) on the opposite side of the bank note transport path.

FIG. 4 depicts an embodiment of the present invention that utilizes twoMRD devices (204 and 404), each configured and positioned along the banknote transport path to detect one surface of the passing bank note(202). As shown, the top MRD (204) and the bottom MRD (404) (or thefirst and second MRDs, respectively) utilize a similar magnetoresistivesensor array configuration (208 and 408). This allows the embodiment toobtain magnetic pattern data from both sides of the bank note as thenote passes. It is also possible to utilize a first MRD device of oneresolution (such as an 8-channel array) with a second MRD device ofanother resolution (such as a 4-channel array) if such arrangementyields sufficient first and second surface magnetic pattern data tosatisfy the objectives of the operator. For example, the operator mayneed a representative digital image of the front surface of the banknote (which can be provided by the higher-resolution MRD device) andonly an indication of the magnetic features of the back surface of thebank note (which can be provided by the lower-resolution MRD device).Such combinations are clearly within the scope of the invention asclaimed.

Although a configuration using two 8-channel arrays is described herein,it is possible to use a single 16-channel or larger array as well orsome similar combination of MRDs. One of ordinary skill in the art willappreciate that the higher the channel density (and lower the detectionwidth of the channel) that is utilized to obtain the magnetic patterndata, the greater the resolution of the magnetic pattern data that maybe obtained.

FIG. 3 provides a flow diagram of the processing steps taken to imagethe note. The bank note first enters the detector array and the MRDsensors are read to obtain a line scan as the note advances (302) untilthe note is fully scanned (304). Because the magnetoresistive detectorsare passive and monitor changes in magnetic flux, the output of eachdetector channel in the sensor array is simultaneously monitored andcaptured such as with an analog to digital conversion circuitry. Withmultiple captures over a brief period of time (the time it takes for thenote to pass the detector array), it is possible to capture a line scanimage of the magnetic content of the note as representative magneticpattern data.

Once the note is fully scanned, the note data is saved to system memoryfor further processing (306). This memory may comprise volatile storage,non-volatile storage, or a combination of the two. The amount of notedata accumulated with a line scan of the note can be determined bymultiplying the number of channels by the scan rate, and multiplyingthis value by the time it takes for the note to pass through thedetector (308).

Once the magnetic pattern data is accumulated, image processingalgorithms may be employed to construct a digital image representationof the surface of the bank note from the data obtained (310). This imagemay then be retained in a system database where other processingalgorithms may be utilized (312) such as an algorithm that correlatesthe reconstructed image with various actual attributes of the scannednote to create a surface map of features. Other algorithms may comparethe scanned bank note with a standard sample bank note foridentification purposes or determination of wear, damage or alteration.

Once the note is fully processed and the image data is generated,decisions can be made concerning the note (314). For example, the systemmay consider print density or magnetic print distribution whendetermining whether a note should remain in circulation. The system mayalso extract magnetic features from the image data for comparison with areference standard. The system then acts upon the decisions and handlesthe note accordingly (316).

In yet another embodiment, multiple such MRD arrays are present (204 and402)—one on each side of the transport path. FIG. 4 depicts such acombination. As the note passes the two MRD arrays (208 and 404), a linescan of both the front and back of the note is performed and magneticpattern data is obtained. As before, image processing algorithms maythen reconstruct an image from the magnetic pattern data. The image maythen be retained in a database where it may further be correlated withother attributes of the given note.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive. Accordingly, the scope of theinvention is established by the appended claims rather than by theforegoing description. All changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein. Further, the recitation of method steps does not denote aparticular sequence for execution of the steps. Such method steps maytherefore be performed in a sequence other than that recited unless theparticular claim expressly states otherwise.

I claim:
 1. A system for automatically detecting the magnetic featuresof a bank note, the system comprising: a transport device capable oftransporting a bank note; a data processing device capable of executingstored program instructions; a data storage device operably coupled withthe data processing device; a first detector device operably coupledwith the data processing device, the first detector device comprising atleast one magnetoresistive sensor positioned proximate the transportdevice and oriented so as to enable detection of the magnetic featuresof the adjacent surface of the passing bank note; wherein the dataprocessing device is capable of executing stored program instructionscomprising: reading the output of the first detector device to capturethe magnetic pattern data of the adjacent surface of the passing banknote; storing the captured magnetic pattern data in the data storagedevice; and making a determination regarding final processing of thebank note based upon the magnetic pattern data; and a strapper, whereinthe strapper straps a plurality of bank notes into a bundle.
 2. Thesystem of claim 1, the program instructions further comprising: creatinga representative digital image of the detected surface of the bank notefrom the magnetic pattern data.
 3. The system of claim 1 wherein theleast one magnetoresistive sensor comprises a plurality ofmagnetoresistive sensors oriented in a linear array, the arraypositioned perpendicular to the direction of the travel of the banknote.
 4. The system of claim 3 wherein the plurality of themagnetoresistive sensors spans the width of the passing bank note. 5.The system of claim 1 further comprising: a second detector deviceoperably coupled with the data processing device, the second detectordevice comprising at least one magnetoresistive sensor, wherein thesecond detector device is positioned proximate the transport device onthe side of the transport device opposite that of the first detectordevice and oriented so as to enable detection of the magnetic featuresof the surface of the passing bank note opposite that of the firstdetector device.
 6. The system of claim 5, the program instructionscomprising: reading the output of the first detector device to capturethe magnetic pattern data of the surface of the passing bank noteadjacent to the first detector device; storing the captured first sidemagnetic pattern data in the data storage device; reading the output ofthe second detector device to capture the magnetic pattern data of thesurface of the passing bank note adjacent to the second detector device;and storing the captured second side magnetic pattern data in the datastorage device.
 7. The system of claim 6, the program instructionsfurther comprising: creating a representative first digital image of thesurface of the bank note from the first side magnetic pattern data; andcreating a representative second digital image of the surface of thebank note from the second side magnetic pattern data.
 8. The system ofclaim 7, the program instructions further comprising: making adetermination regarding final processing of the bank note based uponeither the first side magnetic pattern data or the second side magneticpattern data.
 9. The system of claim 5 wherein the at least onemagnetoresistive sensor of the second detector device comprises aplurality of magnetoresistive sensors oriented in a linear array, thearray positioned perpendicular to the direction of the travel of thebank note.
 10. The system of claim 9 wherein the plurality of themagnetoresistive sensors of the second detector device spans the widthof the passing bank note.
 11. A method for detecting magnetic featuresof a bank note comprising: transporting the bank note proximate to afirst at least one magnetoresistive sensor; reading the output from thefirst at least one magnetoresistive sensor as the note is adjacentthereto to obtain a first surface magnetic pattern data of the surfaceof the passing note adjacent to the at least one sensor; analyzing thefirst surface magnetic pattern data with a data processing device;processing the bank note based upon the analysis of the first surfacemagnetic pattern data; and bundling the bank note with a plurality ofother bank notes using a strapper.
 12. The method of claim 11 furthercomprising: processing the first surface magnetic pattern data with thedata processing device to construct a representative digital image ofthe bank note.
 13. The method of claim 11 further comprising:determining the magnetic features present on the bank note by analyzingthe first surface magnetic pattern data with the data processing device.14. The method of claim 11 further comprising: transporting the banknote proximate to a second at least one magnetoresistive detector;reading the outputs from the second at least one magnetoresistivedetector as the note is adjacent thereto to obtain second surfacemagnetic pattern data of the surface of the passing note adjacent to thedetector; analyzing the second surface magnetic pattern data with thedata processing device; and making a determination regarding finalprocessing of the bank note based upon the first surface magneticpattern data or the second surface magnetic pattern data.
 15. The methodof claim 14, further comprising: processing the second surface magneticpattern data with the data processing device to construct arepresentative digital image of the bank note.
 16. The method of claim14 further comprising: determining the magnetic features present on thebank note by analyzing the second surface magnetic pattern data with thedata processing device.
 17. The method of claim 11 wherein the first atleast one magnetoresistive sensor comprises a plurality ofmagnetoresistive sensors oriented in a linear array, the arraypositioned perpendicular to the direction of the travel of the banknote.
 18. The method of claim 14 wherein the second at least onemagnetoresistive sensor comprises a plurality of magnetoresistivesensors oriented in a linear array, the array positioned perpendicularto the direction of the travel of the bank note and opposite the firstat least one magnetoresistive sensor.
 19. The method of claim 11,wherein the bank note is a U.S. bank note.
 20. The method of claim 19,wherein the U.S. bank note is a $20.00 bank note and wherein themagnetic features are selected from a group consisting of a magnetic inkand a magnetic strip of the U.S. bank note.